Effect of Pericapsular Nerve Group Block with Wound Infiltration vs Modified Supra-Inguinal Fascia Iliaca Block on Postoperative Analgesia in Adult Patients Undergoing Total Hip Arthroplasty - A Randomized Clinical Trial.

Purpose: Pericapsular nerve group (PENG) block and supra-inguinal fascia iliaca block (S-FICB) provides incomplete analgesia for total hip arthroplasty (THA) due to anatomical limitations. This study compares two modified approaches-PENG block with wound infiltration (WI) and a modified S-FICB-to identify the optimal analgesic technique for THA.

Patients and methods: Eighty-six subjects were randomly allocated to either the PENG block + WI group or the modified S-FICB group. The primary outcome was the postoperative numeric rating scale (NRS) pain scores (rest/hip adduction) at 6 hours. The secondary outcomes were pain scores at 12, 24, 48 hours postoperatively and postoperative day 5, the incidence of postoperative quadriceps motor block at 6, 12, 24, 48 hours and postoperative day 5, the mean blood pressure (MAP) at five time points, patient-controlled intravenous analgesia (PCIA) usage and adverse effects such as the incidence of rescue analgesia, local anesthetic systemic toxicity (LAST), postoperative hip infection, the incidence of postoperative nausea and vomiting (PONV) within 5 days after surgery.

Results: PENG + WI group had lower NRS at rest (6h) (95% CI 0.51-1.64, p<0.001). Compared with the PENG block + WI, the modified S-FICB resulted in a higher incidence of quadriceps motor block at 6 hours (82.1% vs 25.6%; OR=13.257, 95% CI 4.46-39.38; p<0.001) and 12 hours (71.8% vs 41%; OR=3.659, 95% CI 1.42-9.42; p=0.001).

Conclusion: PENG block + WI provides sufficient postoperative analgesia with no quadriceps motor block compared to modified S-FICB, supporting early ambulation and in line with the enhanced recovery after surgery (ERAS) protocols.